Air filtration system, air filtration device, and air filtration module for use therewith

ABSTRACT

The present disclosure generally relates to an air filtration system, an air filtration device, and an air filtration module for removing ultra-fine particles (UFPs), pathogens (e.g., viruses, bacteria, etc.), volatile organic compounds (VOCs), oxides or odors. The systems, devices, and filter modules of the disclosure perform at enhanced filter and power efficiencies. An air filtration system is provides that includes a docking base for receiving a removable, portable air filtration device in fluid communication with the docking base. In certain embodiments, the air filtration system further includes the removable, portable air filtration device. The portable air filtration device may optionally include an air filtration module.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.17/152,568, filed Jan. 19, 2021, entitled “AIR FILTRATION SYSTEM, AIRFILTRATION DEVICE, AND AIR FILTRATION MODULE FOR USE THEREWITH,” whichis a continuation of U.S. patent application Ser. No. 16/900,501, filedJun. 12, 2020, entitled “AIR FILTRATION SYSTEM, AIR FILTRATION DEVICE,AND AIR FILTRATION MODULE FOR USE THEREWITH,” now U.S. Pat. No.10,926,209, which is a continuation-in-part of U.S. patent applicationSer. No. 16/895,741, filed Jun. 8, 2020, entitled “AIR FILTRATIONSYSTEM, AIR FILTRATION DEVICE, AND AIR FILTRATION MODULE FOR USETHEREWITH,” now U.S. Pat. No. 10,870,076, issued Dec. 22, 2020, and is acontinuation-in-part of U.S. Design patent application No. 29/737,110,filed Jun. 5, 2020, entitled “AIR FILTRATION SYSTEM,” U.S. Design patentapplication No. 29/737,141, filed Jun. 5, 2020, entitled “AIR FILTRATIONSTAND,” U.S. Design patent application No. 29/737,148, filed Jun. 5,2020, entitled “AIR FILTRATION MODULE,” U.S. Design patent applicationNo. 29/737,150, filed Jun. 5, 2020, entitled “AIR FILTRATION MODULE,”and U.S. Design patent application No. 29/737,154, filed Jun. 5, 2020,entitled “AIR FILTRATION DEVICE,” the entire contents of which areincorporated herein by reference in their entireties for all purposes.

TECHNICAL FIELD

This disclosure relates to air filtration, and more particularly to anair filtration system, an air filtration device, and an air filtrationmodule.

BACKGROUND OF THE INVENTION

Currently, high efficiency air filtration is typically achieved bymoving ambient air through either a high efficiency particulate air(HEPA) or an ultra-low penetration air (ULPA) filtration system. HEPAand ULPA filtration are capable of achieving relatively low particulatelevels, but require a substantial system pressure drop to transport airthrough the large, dense filters necessary for effective particulatecollection. Additionally, current HEPA and ULPA filtration systemsgenerally do not remove volatile organic compounds (VOCs), oxides orodors.

There remains a need in the art for air filtration systems and methodscapable of achieving high efficiency air filtration, together withremoval of other contaminants such as VOCs.

SUMMARY OF THE INVENTION

In one aspect, the present disclosure generally relates to an airfiltration system, an air filtration device, and an air filtrationmodule for removing ultra-fine particles (UFPs), pathogens (e.g.,viruses, bacteria, etc.), volatile organic compounds (VOCs), oxides orodors. The systems, devices, and filter modules of the disclosureperform at enhanced filter and power efficiencies.

In certain aspects, an air filtration system is provided that includes adocking base for receiving a removable, portable air filtration devicein fluid communication with the docking base. In certain embodiments,the air filtration system further includes the removable, portable airfiltration device. The portable air filtration device may optionallyinclude an air filtration module.

In certain aspects, the air filtration system generally comprises adocking base including a docking opening for receiving a portable airfiltration device in fluid communication with the docking base; one ormore unfiltered air inlets for directing unfiltered air to a portableair filtration device when docked in the docking opening; an air outletfor directing air into a portable air filtration device when docked inthe docking opening; a removable secondary media retention feature; andone or more sound dampening features to reduce air flow noise and/orvibrational noise during use.

In certain aspects, a portable air filtration device is provided, whichmay be used alone or which may be interfaced with the docking base. Theportable air filtration device may include a device housing including anexternal air intake for directing unfiltered air into the device; afilter module disposed within the housing; a fan plenum assemblyincluding at least one fan to draw input air into the device and togenerate a positive pressure air flow through the device; wherein thefan plenum assembly is located upstream of the filter module such thatinput air flow is directed from the fan plenum assembly into an input,turbulent air flow region of the filter module during use.

In some embodiments, the fan plenum assembly may comprise a fan airintake side, a fan air outlet side, and a fan plenum seal on the fan airoutlet side of the fan plenum assembly interfaced with the fan plenumattachment seat of the filter module to form an air tight seal betweenthe fan plenum assembly and the filter module.

In yet other aspects, a filter module is provided, which may be used inconnection with the portable air filtration device or air filtrationsystems of the disclosure. The filter module may comprise an externalhousing having a filtered air outlet for directing filtered air from thedevice; an internal chassis having a face plate including an input airinlet for directing input air into the filter module and a fan plenumattachment seat for securing the filter module to a fan plenum assembly;at least two primary filter media, wherein the at least two primaryfilter media are secured to the internal chassis in a spaced apartorientation in a parallel air flow configuration; wherein the internalchassis is positioned substantially within the external housing with theface plate sealed to the perimeter of a surface of the external housingso as to form the exterior of the filter module, with the at least twoprimary filter media located within the filter module so as to separatean input air flow region from a filtered air flow region within thefilter module; and wherein an input, turbulent air flow region iscreated within the filter module in a space between the spaced apartprimary filter media during use.

In certain embodiments, the primary filter media may be pleatedcomposite primary filter media that are over-molded into a structuralframe, and the structural frame is secured to the internal chassis.

In yet other embodiments, the internal chassis further comprises aninput air flow path seal opposite the input air inlet, and opposed sidewalls, each having one or more filter media retention features thatsecure the at least two primary filter media to the side walls of theinternal chassis; and wherein the input, turbulent air flow region iscreated within the filter module in a space between the chassis inputair inlet, the chassis input air flow path seal, the chassis opposedside walls, and the spaced apart primary filter media during use.

These and other aspects of the invention are evident in the drawings andin the description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an exemplary air filtrationsystem with a portable air filtration device inserted into a dockingbase, in accordance with embodiments of the disclosure.

FIG. 2 illustrates a perspective view of an exemplary air filtrationsystem with a portable air filtration device removed from a dockingbase, in accordance with embodiments of the disclosure.

FIG. 3 illustrates a perspective view of an exemplary air filtrationsystem having a docking base with no portable air filtration systemdocked, in accordance with embodiments of the disclosure.

FIG. 4 illustrates an exploded view of an exemplary air filtrationsystem, in accordance with embodiments of the disclosure.

FIG. 5 illustrates a perspective view of an exemplary air filtrationsystem having a docking base with no portable air filtration systemdocked and the secondary media retention feature and secondary mediaremoved, in accordance with embodiments of the disclosure.

FIG. 6 illustrates an exploded perspective view of an interior frame ofa docking base, in accordance with embodiments of the disclosure.

FIGS. 7A-7D illustrate exemplary secondary media, in accordance withembodiments of the disclosure. FIG. 7A shows a perspective top view ofan exemplary secondary media. FIG. 7B shows a perspective bottom view ofan exemplary media. FIG. 7C shows a cross section of the exemplarysecondary media of FIGS. 7A-7B, and FIG. 7D shows a detail of theexemplary secondary media.

FIG. 8 illustrates a perspective view of an exemplary portable airfiltration device with a filter module inserted, in accordance withembodiments of the disclosure.

FIG. 9 illustrates a bottom perspective view of the portable airfiltration device of FIG. 8, in accordance with embodiments of thedisclosure.

FIG. 10 illustrates a perspective view of an exemplary portable airfiltration device with a filter module released from the housing of thedevice, in accordance with embodiments of the disclosure.

FIG. 11 illustrates a perspective view of an exemplary portable airfiltration device with a filter module removed from the housing of thedevice, in accordance with embodiments of the disclosure.

FIG. 12 illustrates a top perspective view of an exemplary portable airfiltration device without a filter module in the housing of the device,in accordance with embodiments of the disclosure.

FIG. 13A-13B illustrates a fan plenum assembly, in accordance withembodiments of the disclosure. FIG. 13A shows a front view of a fanplenum assembly, while FIG. 13B shows a cross section of a fan plenumseal of the fan plenum assembly of FIG. 13A.

FIG. 14 illustrates a perspective view of fan plenum assembly sealed inan air tight configuration to a filter module, in accordance withembodiments of the disclosure.

FIG. 15 illustrates cross section of an exemplary portable airfiltration device without a filter module in the housing of the device,in accordance with embodiments of the disclosure.

FIG. 16 illustrates a fan plenum assembly with an air flow pathdiffuser, in accordance with embodiments of the disclosure.

FIGS. 17A-17B illustrate an exemplary pre-filter media, in accordancewith embodiments of the disclosure. FIG. 17A shows a perspective view ofa pre-filter media, while FIG. 17B shows a detail cross-section of thepre-filter media.

FIG. 18 illustrates a perspective view of a filter module, in accordancewith embodiments of the disclosure.

FIG. 19 illustrates a cross-section of a filter module, in accordancewith embodiments of the disclosure.

FIG. 20 illustrates a perspective view of an alternative embodiment of afilter module, in accordance with embodiments of the disclosure.

FIG. 21A-21B illustrates top (FIG. 21A) and bottom (FIG. 21B) view of afilter module, in accordance with embodiments of the disclosure.

FIG. 22 illustrates a bottom perspective view of a filter module, inaccordance with embodiments of the disclosure.

FIG. 23 illustrates a front perspective view of an internal chassis of afilter module, in accordance with embodiments of the disclosure.

FIG. 24 illustrates a back perspective view of an internal chassis of afilter module, in accordance with embodiments of the disclosure.

FIG. 25 illustrates a detail perspective view of an internal chassis ofa filter module secured to primary filter media, in accordance withembodiments of the disclosure.

FIG. 26A-26B illustrate an internal chassis of a filter module securedto primary filter media, in accordance with embodiments of thedisclosure. FIG. 26A shows a cross section of the internal chassissecured to primary filter media, while FIG. 26B shows a detailcross-section of an exemplary seal between the primary filter media andthe internal chassis.

FIG. 27 illustrates a perspective cross-section of a filter moduleincluding to an internal chassis secured to primary filter media, inaccordance with embodiments of the disclosure.

FIG. 28 illustrates an exploded perspective view of a filter module, inaccordance with embodiments of the disclosure.

FIG. 29 illustrates a perspective view of the insertion of an internalchassis secured to primary filter media into the external housing of afilter module, in accordance with embodiments of the disclosure.

FIG. 30A-30D illustrate an exemplary primary filter media, in accordancewith embodiments of the disclosure. FIG. 30A shows a top view of aprimary filter media, FIG. 30B shows a cross-section of the filter mediaalong the direction of the filter media pleating, FIG. 30C shows across-section of the primary filter media across the direction of thefilter media pleating, and FIG. 30D shows a detail cross-section of theprimary filter media.

FIG. 31 depicts a block diagram of example components of a filtrationdevice, in accordance with an embodiment of the disclosure.

FIG. 32 shows an example controller of a filtration device, inaccordance with an embodiment of the disclosure.

FIG. 33 is an example computing system that may implement varioussystems and methods discussed herein.

FIG. 34 illustrates particle size removal efficiency of an exemplary airfiltration system, in accordance with embodiments of the disclosure.

FIG. 35 illustrates concentration change for various challenge chemicalsduring testing using an exemplary air filtration system, in accordancewith embodiments of the disclosure.

FIG. 36 illustrates for various challenge chemicals during testing usingan exemplary air filtration system, in accordance with embodiments ofthe disclosure.

DETAILED DESCRIPTION

The present disclosure generally relates to an air filtration system, anair filtration device, and an air filtration module for removingultra-fine particles (UFPs), pathogens (e.g., viruses, bacteria, etc.),volatile organic compounds (VOCs), oxides, odors, and the like.

In certain aspects, an air filtration system is provided that includes adocking base for receiving a removable, portable air filtration devicein fluid communication with the docking base. During use, the portableair filtration device may be removably docked in the docking base influid communication with the docking base, and the air filtration devicemay operate to generate air flow into and through the docking base, intothe air filtration device, and through a filter module housed within theair filtration device to thereby produce filtered air, which exits fromthe docked air filtration device.

In certain aspects, the air filtration system generally comprises adocking base including a docking opening for receiving a portable airfiltration device in fluid communication with the docking base; one ormore unfiltered air inlets for directing unfiltered air to a portableair filtration device when docked in the docking opening; an air outletfor directing air into a portable air filtration device when docked inthe docking opening; a removable secondary media retention feature(optionally including secondary media); and one or more sound dampeningfeatures to reduce air flow noise and/or vibrational noise during use.

The portable air filtration device may include a device housingincluding an external air intake for directing unfiltered air into thedevice; a filter module disposed within the housing; a fan plenumassembly including at least one fan to draw input air into the deviceand to generate a positive pressure air flow through the device; whereinthe fan plenum assembly is located upstream of the filter module suchthat input air flow is directed from the fan plenum assembly into aninput, turbulent air flow region of the filter module during use.

The filter module may comprise an external housing having a filtered airoutlet for directing filtered air from the device; an internal chassishaving a face plate including an input air inlet for directing input airinto the filter module and a fan plenum attachment seat for securing thefilter module to a fan plenum assembly; at least two primary filtermedia, wherein the at least two primary filter media are secured to theinternal chassis in a spaced apart orientation in a parallel air flowconfiguration; wherein the internal chassis is positioned substantiallywithin the external housing with the face plate sealed to the perimeterof a surface of the external housing so as to form the exterior of thefilter module, with the at least two primary filter media located withinthe filter module so as to separate an input air flow region from afiltered air flow region within the filter module; and wherein an input,turbulent air flow region is created within the filter module in a spacebetween the spaced apart primary filter media during use.

The systems, devices, and filter modules of the disclosure perform atenhanced filter and power efficiencies. Without intending to be limitedby theory, the systems and devices described herein generally utilize alow face velocity of less than or equal to 5 cm/s at the surface of thefiltration media (i.e., particle velocity at the surface of thefiltration media) to achieve desired filtration efficiencies.

In certain embodiments, the devices and systems of the disclosureprovide a particle velocity at the surface of a primary filtercomponent(s) (face velocity) less than or equal to 5 cm/s, 4 cm/s, 3cm/s, 2 cm/s, or 1 cm/s. In certain aspects, at such face velocities,with the filtration module described herein, the collection efficiencyfor the filtration media of the filtration module is greater than99.99%, 99.999%, 99.999%, 99.9999%, or 99.99999%, which greatly outperforms HEPA filters known in the art. Further, in certain embodiments,using a face velocity less than or equal to 5 cm/s, 4 cm/s, 3 cm/s, 2cm/s, or 1 cm/s, also produces a lower pressure drop across thefiltration module, as compared to using a higher face velocity, e.g.,greater than 5 cm/s, which is beneficial for overall system efficiency(e.g., less demanding for the blower/fan(s)).

Aspects of the present disclosure generally relate to an air filtrationsystem for removing ultra-fine particles (UFPs), pathogens (e.g.,viruses, bacteria, etc.), volatile organic compounds (VOCs), oxides orodors. With reference to FIG. 1, in one embodiment, an air filtrationsystem 100 of the disclosure includes a docking base 104 for receiving aremovable, portable air filtration device 102 in fluid communicationwith the docking base 104. In certain embodiments, the air filtrationsystem 100 further includes the removable, portable air filtrationdevice 102. The portable air filtration device 102 may optionallyinclude an air filtration module 106 of the disclosure. In this regard,FIG. 2 illustrates a portable air filtration device 102 removed fromdocking base 104, and FIG. 3 illustrates docking base 104 withoutportable air filtration device 102. During use, a portable airfiltration device 102 may be removably docked in the docking base 104,and the air filtration device 102 may operate to generate a positivepressure air flow through the docking base 104, into the air filtrationdevice 102, and through a filter module 106 housed within the airfiltration device 102. In one implementation, the filtration device 102achieves extremely high filter efficiencies of at least 99.9999% at lowface velocities less than or equal to 5 cm/s. At such face velocities,the filtration device 102 has a filter efficiency of 99.99999% forparticles below 300 nm, as well as pathogens of similar size.

With reference to FIG. 4, in certain embodiments, the docking base 104includes a docking opening 120 for receiving a removable, portable airfiltration device 102; one or more unfiltered air inlets 122 fordirecting unfiltered air to a removable, portable air filtration device102 when docked in the docking opening 120; an air outlet 124 fordirecting air into a removable, portable air filtration device 102 whendocked in the docking opening; a removable, secondary media retentionfeature 126; and one or more sound dampening features (not shown) toreduce air flow noise and/or vibrational noise during use. The dockingbase may further include a power charging port (not shown) in electricalcommunication with a portable air filtration device 102 when docked, andan air entry mesh 128 at each of the one or more unfiltered air inlets122 to remove large particulates from unfiltered air drawn into thedocking base 104 during use. FIG. 5 illustrates the secondary mediaretention 126 with secondary filter media 108 removed from the dockingbase 104.

In certain embodiments, air enters into the docking base 104 initiallythrough the air entry mesh 128 at each of the unfiltered air inlets 122.Although illustrated with the air entry mesh 128 at each of theunfiltered air inlets 122 disposed at each side of the docking base 104,the disclosure is not so limited and alternative configuration andorientations are within the scope of the disclosure. For instance,unfiltered air inlets 122 and related air entry mesh 128 may beconfigured at the front and back or along the side walls of the dockingbase 104. In one implementation, air entry meshes 128 are separatecomponents which are attached to the docking base 104. In anotherimplementation, air entry meshes 128 are integrated into the dockingbase 104 as a unitary component. Air entry meshes 128 may be constructedfrom a light-weight, durable material.

Air entry meshes 128 serve as an initial entry port for input air toenter the docking base 104 and thereby the air filtration system 100,and is therefore also a region of large particle filtration. Theopenings of the air entry mesh 128 are sized and spaced such that eachof the openings are large enough to reduce resistance to air being drawninto the docking base 104 and small enough to prevent very largeparticles from entering the docking base 104. In one implementation, theopenings in the air entry mesh 128 are generally slat shaped openings ofa finite width and length arranged in parallel. The parallel arrangementof the openings allows for a linear reduction in flow resistance that isdirectly related to the number of openings without sacrificing theminimum opening dimension, which in turn governs the size of particlesthat are allowed to pass through the openings.

With reference to FIG. 6, in certain embodiments, the docking base 102may be configured to form one or more air flow paths between theunfiltered air inlets and the air outlet. By way of example, the dockingbase 102 may be configured to include an interior docking frame 130 thatincludes the one or more air flow paths located between the dockingopening 120 for receiving a portable air filtration device 102 and theexterior of the docking base 104. The air flow paths may be formedbetween one more baffles 132 or similar flow direction surfaces. Theinterior docking frame 130 may also be configured to include one or moreopenings 134, 136 to accommodate the portable air filtration device, thesecondary filter retention feature, respectively. The air flow paths maydirect air from the unfiltered air inlet inlets into the docking base,under the secondary filter media (if present) and into the portable airfiltration device. In certain embodiments, the one or more air flowpaths may form non-turbulent air flow paths (e.g., transitional orlaminar air flow paths). In certain embodiments, the sound dampeningfeatures (not shown) may be located along or adjacent to the air flowpaths, at the bottom of the docking base, or a combination thereof.

In certain embodiments, the removable, secondary media retention feature126 may be located in the air flow path between the unfiltered airinlets 122 and the air outlet 124. By way of example, the removable,secondary media retention feature 126 may be configured in any suitablemanner, e.g., as a clip-on frame, a slide-in frame, etc. In certainaspects, the docking base 104 may further comprises a secondary media108 housed in the removable secondary media retention feature 126. Thesecondary media retention feature 126 and secondary media 108 may beconfigured to provide a desired air flow residence time through thesecondary media 108 during use, e.g., so as to maximize filteringefficiency of the secondary media 108.

In certain embodiments, the secondary media 108 may comprise anactivated carbon media to remove volatile organic compound (VOCs),oxides, odors, and combinations thereof. By way of example, theactivated carbon media be comprised of at least two electrostaticallycharged scrim layers enclosing granulated activated carbon. In certainembodiments, between 150 grams to about 175 grams, preferably about 160grams of the granulated activated carbon is enclosed within theelectrostatically charged scrim layers of the activated carbon media. Byway of example, the granulated activated carbon may be a 12×40 standardsieve size coconut shell activated carbon, a 6×12 standard sieve sizecoconut shell activated carbon, or a 4×8 standard sieve size coconutshell activated carbon. In other embodiments, the secondary media 108may comprise a pleated composite primary filter media that isover-molded into a structural frame.

With reference to FIGS. 7A-7D, an exemplary embodiment of a secondarymedia filter 700 is illustrated, with FIG. 7A showing a top view, FIG.7B showing a bottom view, and FIG. 7C showing a cross-section of thesecondary media filter 700. The secondary media filter 700 includes abottom container 702 and a lid 704. With reference to FIG. 7D, a detailof the interface between the top lid 704 and the bottom container 704 isillustrated, showing the top lid 704 and bottom container 702 beingbonded together at connection features 708 to form an internal mediaenclosure 706. Any suitable method for bonding the top lid 704 to thebottom container 702 may be used, including, e.g., ultrasonic welding,thermal bonding, adhesives, etc. Each of the bottom container 702 andtop lid 704 comprise multiple air flow openings 702 a, 704 a,respectively, to allow air flow through an internal media enclosure 706.As illustrated, the top lid 704 includes four air flow openings 704 a,and the bottom container 702 includes eight air flow openings 702 a.However, the disclosure is not so limited, and any suitable air flowopening configuration, e.g., having more or fewer air flow openings,sufficient to provide desired airflow and filter media residence timemay be utilized. By way of example, in the embodiment exemplified, eachair flow opening is covered with a scrim layer 710 that allows for airflow through the opening. In certain embodiments, the scrim layer is anelectrostatically charged scrim layer, e.g., nonwoven scrim substrate.The internal media enclosure comprises activated carbon filtration media712.

In certain embodiments, the air filtration system 100 optionallyincludes a user control device 112. The user device 112 is incommunication with the portable filtration device 102 for controllingthe operations of the filtration device 102. The user device 112 isgenerally any form of computing device, such as remote control, a mobiledevice, tablet, personal computer, multimedia console, set top box, orthe like, capable of interacting with the filtration device 102. Theuser device 112 may communicate with the filtration device 102 via awired (e.g., Universal Serial Bus (USB) cable) and/or wireless (e.g.,Bluetooth or WiFi) connection. In addition to controlling the operationof the filtration device 102, the user device 112 may be used to monitorthe performance of the filtration device 102, including filter andcollection efficiency, power consumption, system pressure, air flowrates, and the like. The user device 112 further provides real timeinformation on power level, fan speed, filter life, and pressure alarm.

Docking base 104 may be constructed from a light-weight, durablematerial. By way of non-limiting example, suitable materials forconstruction of docking base 104 may include anodized aluminum,titanium, titanium alloys, aluminum alloys, fibrecore stainless steel,carbon fiber, Kevlar™, polycarbonate, acrylonitrile-butadiene-styrene(ABS), polyurethane, or any combination of the mentioned materials. Thesound dampening features may be formed from any suitable materials knownin the art for such purposes, e.g., polyurethane foam, silicone, cottonfiber, etc.

In other aspects, the present disclosure relates to a portable airfiltration device 102, which may be used independently or in connectionwith the air filtration system 100 disclosed herein. In certainembodiments, the portable air filtration device 102 may be configured tointerface in fluid communication with the docking stand 104 of the airfiltration system 100 disclosed herein. Alternatively, the portable airfiltration device 102 may operate in a “stand-alone” configurationwithout the docking stand of the air filtration system. In yet otherembodiment, the portable air filtration device 102 may interface withalternative docking stands (not shown). In yet other embodiments, theportable air filtration device 102 may interface in fluid communicationwith face masks, air-flow hoses, or breathing tubes of power-assistedair purifying (PAAP) respirators, continuous positive airway pressure(CPAP) machines, bi-level positive airway pressure (BiPAP) machines,and/or ventilators (not shown).

With reference to FIGS. 4 and 8, in certain embodiments, the portableair filtration device 102 includes a device housing 200 including anexternal air intake 216 for directing input air into the filtrationdevice 102. The filtration device 102 also includes a fan plenumassembly 218 disposed within the device housing 200 and including atleast one fan 220 to draw input air into the filtration device 102 andto generate a positive pressure air flow through the filtration device102 (see FIG. 15). As described herein, the filtration device 102 mayalso include a filter module 106 disposed within the device housing 200.The filter module 106 may include an external filter module housing 300having a filtered air outlet 302 for directing filtered air from thefiltration device 102, an internal chassis 304 for securing at least twoprimary filter media 306, and a fan plenum attachment seat 308 forsecuring the filter module 106 to the fan plenum assembly 218 (see FIG.19). In certain embodiments, the fan plenum assembly 218 is locatedupstream of the filter module 106 within the device housing 200 suchthat input air flow is directed from the fan plenum assembly 218 intothe filter module 106 during use.

In certain embodiments, the filtration device 102 includes a devicehousing 200 to enclose the internal components of the filtration device102. In one implementation, device housing 200 includes a removablecover 202 which, when attached or affixed to the housing encases theinternal components of the filtration device 102. For instance,removable cover 202 may be used to access compartments holding internalcomponents such as pre-filter 210, one or more power source(s) 208, etc.It will be appreciated, however, that more or fewer covers may beincluded for accessing a variety of different internal components. Whilethe removable cover 202 as illustrated extends the entire length of oneside of housing 200, the disclosure is not so limited.

Device housing 200 may also include a user control interface 204 forproviding operation of the device. In certain embodiments, the housing200 may also include one or more filtration module releasable securingfeatures 206, for releasably securing the filtration module to thefiltration device housing. By way of non-limiting example, suchreleasable securing features may be configured as a clip, snap, slide,set screw, or similar releasable fixing element. In certain embodiments,the external filter module housing 300 may include one or more housingretention features 330 that may be sized and shaped so as to interfacewith filtration module releasable securing features 206.

With reference to FIG. 9, a perspective bottom view of the filtrationdevice 102 is shown. In certain embodiments, air enters into thefiltration device 102 initially through the air entry mesh 212 attachedor integrated at the bottom of the housing 200. In some embodiments, thebottom of housing 200 includes an opening or other type of access portto allow for attachment/integration of an air entry mesh 212. Althoughillustrated with the air entry mesh 212 disposed at the bottom of thehousing 200, the disclosure is not so limited and alternativeconfiguration and orientations are within the scope of the disclosure.For instance, the air entry mesh 212 may be configured on any of theother walls of housing 200. In one implementation, the air entry mesh212 is a separate component which is attached to the housing 200. Inanother implementation, the air entry mesh 212 is integrated into thehousing 200 as a unitary component. The air entry mesh 212 may beconstructed from a light-weight, durable material.

The air entry mesh 212 serves as an initial entry port for input air toenter the filtration device 102 and is therefore also a region of largeparticle filtration. The openings of the air entry mesh 212 are sizedand spaced such that each of the openings are large enough to reduceresistance to air being drawn into the filtration device 102 and smallenough to prevent very large particles from entering the filtrationdevice 102. In one implementation, the openings in the air entry mesh212 are generally openings having a defined shape (e.g., cylinders,pentagons, hexagons, octagons, etc.) of a finite thickness and diameterarranged in parallel. The parallel arrangement of the openings allowsfor a linear reduction in flow resistance that is directly related tothe number of openings without sacrificing the minimum openingdimension, which in turn governs the size of particles that are allowedto pass through the openings.

In particular embodiments, the openings have a diameter ranging fromapproximately 1.1 mm to approximately 2.2 mm, preferably fromapproximately 1.3 mm to approximately 1.6 mm, e.g., approximately 1.4mm, approximately 1.5 mm, etc. In certain embodiments, the openings havea pitch between holes of approximately 2.2 mm to approximately 2.6 mm,preferably approximately 2.25 mm to approximately 2.4 mm. It will beappreciated that these dimensions are exemplary only and the openingsmay include larger or smaller dimensions.

As described herein, in addition to superior filtration efficiency, thefiltration device 102 achieves reduced power consumption. Withoutintending to be limited by theory, generally, the functionality of afilter over time has a direct effect on the performance and efficiencyof a power source 208. For instance, as a filter is loaded withparticles the overall resistance of the filter is increased. When thefilter resistance increases, it requires more energy output from thepower source 208 to drive the fans 220 at the flow rate/face velocityset in the unloaded state. As such, in some embodiments, the airfiltration system 100 and/or filtration device 102 includes secondaryfilters 108 and/or pre-filters 210 to extend the life of the filtermodule 106 and to reduce power consumption.

The power source 208 may utilize, without limitation, direct current(DC), alternating current (AC), solar power, battery power, and/or thelike. In one particular implementation, the power source 208 includesone or more lithium ion batteries that are rechargeable with a DC 15Vpower adapter. In certain embodiments, the docking base 104 may includea charging port and electrical communication to facilitate charging ofthe power source 208, the filtration device 102 may including a chargingport and electrical communication to facilitate charging of the powersource 208, or any combination thereof. In certain embodiments, thebatteries of the power source 208 are hot swappable during operation ofthe filtration device 102. For example, during use, if one or more ofthe batteries are low, the batteries may be can replaced individuallywithout ever turning the filtration device 102 off.

In certain embodiments, the controller manages the power consumption ofthe filtration device 102 by controlling the charging and discharging ofthe one or more power sources 208. In certain aspects, the controllermay receive an input from the user device 112 and/or controls on thefiltration device 102 and in response, may activate the one or more fans220 to provide airflow through the filtration device 102 at various flowrates. In one embodiment, the user device 112 communicates with thefiltration device 102 via a wired connection or wireless connection. Thecontroller may also alter the speed of the fans 220 according to thecharge level of the power sources 208 and may convert a provided inputpower through a power connector to an appropriate charging voltage andcurrent for the power sources 208. The controller further manages otheroperations of the filtration device 102. For example, the controller maymanage status light emitting diodes (LEDs) that indicate the currentoperational mode of the filtration device 102, the operation of one ormore sensors, and the like. The LEDs may indicate when the filtersand/or other components need replacing.

With reference to FIG. 10 and FIG. 11, in some embodiments, devicehousing 200 may be configured with opening 214 or other type of accessport to allow for insertion of filter module 106, to allow for fluidcommunication between the fan plenum assembly and fan(s) (not shown),and to allow for air flow out of the filtration device 102, as describedherein. FIG. 12 illustrates a perspective top view of the filtrationdevice 102 with the filter module 106 removed to show the fan air outletside 224 and fan plenum seal 226 of the fan plenum assembly 218, whichprovides for air tight securement of the fan plenum assembly 218 (andthereby the device housing 200) to the filter module 106 when the filtermodule 106 is inserted in opening 214 and interfaced with the fan plenumseal 226.

In certain embodiments, the filter module 106 may be removed forreplacement through the opening 214 using one or more filtration modulereleasable securing features 206. More specifically, the filter module106 may be spring loaded into the filtration device 102 and may beremoved by pushing the filtration module releasable securing features206 in and slightly pushing down on the filter module 106 to release thefilter module 106 (FIG. 10), and the filtration module 106 may beremoved from the filtration device 102 (FIG. 11).

The device housing 200 may be a variety of shapes and sizes. Forexample, in one particular implementation, the overall dimensions of thehousing 200 range from approximately 10″×3″×8″ to approximately16″×7″×12″. It will be appreciated that these dimensions are exemplaryonly and the housing 200 may be modified to accommodate larger orsmaller dimensions. For example, by keeping the same proportions, thefiltration device 102 can function properly by being reduced by apercentage between 0 and 60% of these dimensions.

The device housing 200 may be constructed from a light-weight, durablematerial. By way of non-limiting example, suitable materials forconstruction of the housing 200 include anodized aluminum, titanium,titanium alloys, aluminum alloys, fibrecore stainless steel, carbonfiber, Kevlar™, polycarbonate, acrylonitrile-butadiene-styrene (ABS),polyurethane, or any combination of the mentioned materials.

In certain aspects of the disclosure, during operation, the at least onefan 220 pulls input air through the air entry mesh 212 and into thefiltration device 102 through a fan air outlet side 224. If thefiltration device 102 is docked in the docking base 104, the at leastone fan 220 pulls input air through the air entry mesh 128 of thedocking base 104, through air flow paths of the docking base 104 (andoptionally secondary filters 108), and then through the air entry mesh212 of the filtration device 102. After entering the filtration device102 through the air entry mesh 212, input air is drawn through optionalpre-filters 210 (as described herein). Optional pre-filters 210 filterlarge particles that may potentially build up on and/or damage the fans220 and/or a filter module 106.

With reference to FIG. 13A, in certain embodiments, the fan plenumassembly 218 includes a fan air intake side 222; a fan air outlet side224; and a fan plenum seal 226 on the fan air outlet side 224 of the fanplenum assembly 218, which may be interfaced with a fan plenumattachment seat of the filter module to thereby form an air tight sealbetween the fan plenum assembly 218 and the filter module. The fanplenum assembly 218 may also include a fan chamber 220 c, to house theone or more fans (not shown, and a pre-filter retention feature 240,sized and shaped so as to accommodate an optional pre-filter (notshown). FIG. 13B illustrates a cross-section of the fan plenum seal 226comprising an accordion style gasket. However, the disclosure is not solimited, and any suitable sealing configuration may be utilized to forman air tight seal between the fan plenum assembly 218 and the filtermodule 106, e.g., O-rings, silicone gaskets, etc.

With reference to FIG. 14, an exemplary embodiment is shown illustratinga filter module 106 secured in an air tight configuration to a fanplenum assembly 218. In certain embodiments, the at least one fan maycomprise a plurality of serially stacked, axial fans 220 a, 220 b withina fan chamber 220 c. Without intending to be limited by theory, asopposed to a parallel configuration (i.e., both fans disposed besideeach other), the series (stacked) configuration allows the pressureoutput to be additive, whereas a parallel configuration results in anincrease in overall flow. The fan plenum assembly may also include apre-filter retention area in the fan air intake side 222 to secure apre-filter 210. An air tight seal may be formed between the filtermodule 106 and the fan plenum assembly 218 via a fan plenum assemblyseat 308 located on the internal chassis 304 of the filter module 106and a fan plenum seal (not shown) located on the fan air outlet side 224of the fan plenum assembly 218. The fan assembly seat 308 may beconfigured to structurally mate with the fan plenum seal so as to forman air tight seal between the filter module 106 and the fan plenumassembly 218.

With reference to FIG. 15, an air filtration device 102 is illustratedincluding opening 214 for insertion of a filtration module (not shown)during use so as to form an air tight seal to a fan plenum assembly 218.The air filtration device 102 may further include a controller (notshown) in electronic communication with a power source 208 (e.g.,comprised of one or more batteries), the controller configured toprovide power from the power source 208 to drive the at least one fan220 a, 220 b during use, and an optional user control device (not shown)in communication with the controller to operate the at least one fan 220a, 220 b. The device housing 200 may also comprise an air entry mesh 214to remove large particulates from input air drawn into the filtrationdevice 102 during use.

In one implementation, the one or more fans 220 a, 220 b operate at highhydrostatic pressures (e.g., 3-5 inches of water) and generate high flowrates up to 300 SLM. In certain implementations, to achieve highefficiency for the filter module 106, the fans 220 a, 220 b operatebetween approximately 50 and 300 SLM. The fans 220 a, 220 b may operateat various speeds, for example, low (100 SLM), medium (130 SLM), andhigh (180 SLM). There may optionally be sound dampening material aroundthe fans. The material may be, without limitation, polyurethane foam,silicone, cotton fiber, etc.

Any suitable fan design and configuration may be utilized in connectionwith present disclosure. For example, in addition to fan power andoutput, fan configurations may be selected based on fan blade size,shape, number, orientation, surface area, and the like. Pressure isproportional to the square of the rotations per minute (RPM). Anincrease in RPM will result in a power increase proportional to the cubeof the RPM. Higher RPM means higher pressure, lower RPM means lowerpressure, thereby requiring more blades. In one implementation, thenumber of fan blades is of less concern than total blade surface area.Blade surface area is the single blade's surface area times the numberof blades. Orientation may also be taken into consideration. Forinstance, if fan blades are too close together, there may not besufficient air between the blades to have adequate performance. In oneimplementation, the fans 220 comprise fan blades that are narrow on thetip to decrease air resistance and will widen toward the hub. The angleof the fan blades may be minimized at the tip and generally increasetoward the hub. In this regard, in one implementation, the transitionfrom the angle at the tip to the angle at the hub may be gradual and/orsmooth to prevent back flow.

The static pressure of the filtration device 102 may be increased byincluding a plurality of fans 220 a, 220 b in a stacked configurationhaving contra-rotating two stage axial impellers. In one implementation,two or more stacked fans 220 a, 220 b are provided, as described above,which rotate in opposite directions with the upstream fan having a pitchangle that is approximately 8-10 degrees higher than the fan furtherdownstream.

With reference to FIG. 16, the one or more fans 220 may direct air flowinto the filter module 106 using a flow transitional diffuser 228disposed downstream of the fans 220. The diffuser 228 includes one ormore surfaces 230 that spread the airflow evenly across the primaryfilter media 306 of the filter module 106, ensuring that particlescollected by the primary filters 306 are not concentrated in any oneregion, thereby increasing the overall lifetime of the primary filters306 and consequently the power sources 208.

In some embodiments, the portable air filtration device 102 may includeat least one pre-filter retention feature 240 that may house apre-filter 210 to remove large particles from the positive pressure airflow. The at least one pre-filter 210 may be located upstream of the fanplenum assembly 218 and/or the filter module 106. The pre-filter 210 mayhave any suitable filter pore size and may be formed in pleated ornon-pleated configurations. For example, the pore sizes of thepre-filter 210 can range from approximately 0.1 micron-900 microns. Suchpore sizes, and pleating/non-pleating configuration generally producevery low pressure drop.

The pre-filter 210 may be formed from any suitable filter materials andmay have any suitable pore size. Further, the pre-filter 210 may beformed in pleated or non-pleated configurations. For instance, incertain embodiments, the pore sizes of the pre-filter material can rangefrom 0.1 micron-900 microns. Such pore sizes, and pleating/non-pleatingconfiguration generally produce very low pressure drop. By way ofnon-limiting example, the pre-filter 210 may be formed from a variety ofsuitable filter materials used in high-efficiency particulate air (HEPA)class filters. For instance, the pre-filter 210 may be formed fromspunbonded polyester nonwoven fabric materials, polytetrafluoroethylene(PTFE), polyethylene terephthalate (PET), activated carbon, impregnatedactivated carbon, or any combination of the listed materials. Thesematerials may also be, optionally, electrostatically charged. In otherembodiments, the pre-filter may include one or more hydrophobic layers,e.g., to minimize intrusion of moisture/water into the device. In oneimplementation, the pre-filter 210 is a single pleated or sheet ofmaterial. In another implementation, the pre-filter is co-pleated orlaminated with other desired materials for combined benefits. In otherembodiments, the pre-filter 210 is a carbon filter that may comprise atleast two electrostatically charged scrim layers enclosing granulatedactivated carbon.

With reference to FIGS. 17A-17B, an exemplary embodiment of a pre-filter800 is illustrated. The pre-filter 800 may comprise a pleated compositepre-filter media 802 that is over-molded 806 into a structural frame804. In certain embodiments, the pleated composite pre-filter media 802includes one or more structural pleat support features 810.

In yet other aspects, the present disclosure provides a filter modulewhich may be used alone or in connection with the portable airfiltration device and/or air filtration systems described herein. Withreference to FIG. 18, in certain embodiments, the air filtration module106 may include an external filter module housing 300 having a filteredair outlet 302 for directing filtered air from the module 106, device102 or system 100. In certain embodiments, the external filter modulehousing 300 may include one or more housing retention features 330 thatmay be sized and shaped so as to interface with filtration modulereleasable securing features. In certain embodiments, the filtered airoutlet 302 may be configured at a grate or grill 312. With reference toFIG. 19, the air filtration module 106 is shown in cross section. Asshown, the air filtration module 106 may include an internal chassis 304having a face plate 310 including an input air inlet 310 a for directinginput air into the filter module 106; at least two filter media 306 a,306 b, secured to the internal chassis 304 in a spaced apart orientationin a parallel air flow configuration during use. In other embodiments,with reference to FIG. 20, the filtered air outlet 302 may be configuredat as cylinder or tube 314. However, the disclosure is not so limited,and any configuration of the air outlet may be used.

FIG. 21A illustrates a top view of the filter module 106, and FIG. 21Billustrates a bottom view of filter module 106. FIG. 22 illustrates aperspective bottom view of filter module 106. As shown, in certainembodiments, internal chassis 304 includes a fan plenum attachment seat308 for securing the filter module 106 to a fan plenum assembly (notshown) in an air tight seal configuration. By way of example, as shownin FIG. 21B, FIG. 22, and FIG. 23, the fan plenum attachment seat 308may be configured as a recessed portion 308 a of the face plate 310 ofinternal chassis 304 sized and shaped so as to structurally mate withthe edge of the fan plenum seal (e.g., the accordion style gasket).

With reference to FIG. 23 and FIG. 24, a front and back perspective viewof an internal chassis 304 of the disclosure is illustrated. In certainembodiments, the internal chassis 304 includes a face plate 310 havingan input air inlet 310 a and a fan plenum attachment seat 308 forsecuring the filter module 106 to a fan plenum assembly (not shown) inan air tight seal configuration, an input air flow path seal 316opposite the face plate 310, and opposed side walls 318, each having oneor more filter media retention features 318 a that secure the primaryfilter media (not shown) to the internal chassis side walls 318. Faceplate 310, side walls 318 and input air flow path seal 316 may furtherinclude spacers 340 to facilitate placement and securement of filtermedia within the internal chassis 304. As shown, the spacers 340 may belocated on an interior surface of the face plate 310, side walls 318 andinput air flow path seal 316, and may be sized, shaped, and located toaid in placement of the filter media within the internal chassis.

As shown, in certain embodiments, the side walls of the internal chassismay be slightly tapered in a direction from the front to back of theinternal chassis (i.e., from the face plate 310 to the input air flowpath seal 316). In this regard, spacers 340 may likewise be of variedlengths along the length of side walls 318 such that the spacersfacilitate placement and securement of the filter media within theinternal chassis 304 at fixed positions relative to the length of theside walls. By way of example, as described in further detail herein,the filter media may be arranged in a spaced apart orientation inintersecting planes so as to provide for parallel air flow between thefilters during use (i.e., as opposed to serial air flow through onefilter and then the other, air flow through one filter or the other inparallel). The spacers 340, together with the filter media retentionfeatures 318 a, may facilitate arrangement of the filter media in thisregard.

In some embodiments, the side walls 318 may be configured to include oneor more wings 304 a to facilitate placement of the internal chassis 304within the external housing of the filter module. The wings 304 a may belocated, e.g., at a taped end of the side walls 318, near the input airflow path seal 316. Without intending to be limited, the wings 304 a maybe sized and shaped to as to accommodate the internal dimensions of thefilter module external housing, and may structurally secure the internalchassis within the housing.

With reference to FIG. 25, in certain embodiments, the spaced apartprimary filter media 306 a, 306 b may be secured, at least in part, tothe side wall 318 of the chassis via the filter media retention features318 a to form an air tight seal between the primary filter media 306 andthe internal chassis 304. In certain embodiments, the filter mediaretention features 318 a of the side walls of the internal chassis 304are selected from clips, grooves, snaps, and combinations thereof.Spacers 340 may facilitate placement and securement of the filter media306 a, 306 b by interfacing with securement tabs 406 of the filterstructural frame 404. As shown, filter securement tabs 406 may restagainst spacers 340 to retain the filter media in one direction, whilefilter media retention features 318 a may secure the filter media fromthe other direction. In certain embodiments, additional bonding features318 b may be used to further secure the filter media to the side walls318, input air flow path seal 316, and/or face plate 310 of the internalchassis 304 and form an air tight seal between the filter media and theinternal chassis.

With reference to FIG. 26A and FIG. 26B, in some embodiments, inaddition to the securement along the side walls, the primary filtermedia 306 a, 306 b may be further secured to the internal chassis 304 atthe input air flow path seal 316, and/or the face plate 310 includingthe input air flow inlet 310 a using a bonding feature 318 b, e.g.,thermal bonding, ultrasonic welding, or adhesives.

With reference to FIG. 19 and FIG. 27, in some embodiments, the spacedapart primary filter media 306 a, 306 b may be located within the filtermodule 106 so as to separate an input air flow region 322 from afiltered air flow region 324 within the filter module 106. In certainembodiments, the input air flow region 324 is created within the filtermodule 106 in a space between the face plate 310, the chassis input airflow path seal 316, the chassis opposed side walls (not shown), and thespaced apart primary filter media 306 a, 306 b during use. As describedabove, in some embodiments, spacers 340 and filter media retentionfeatures 318 a may facilitate placement and securement of filter media306 a, 306 b in the spaced apart orientation so as to separate an inputair flow region 322 from a filtered air flow region 324 within thefilter module 106. In accordance with the disclosure, the filter airflow region 324 is in filtered isolation from input air flow region 322,i.e., air flow is sealed via the air tight seal between the filter media306 a, 306 b and the internal chassis 304 and only available through thefilter media). In certain embodiments, the input air flow region 322 maybe configured so as to provide turbulent air flow within the input airflow region 322 during use.

As illustrated, in certain embodiments, the primary filter media 306 a,306 b are arranged in a spaced apart orientation in intersecting planesso as to provide for parallel air flow between the filters during use(i.e., as opposed to serial air flow through one filter and then theother, air flow through one filter or the other in parallel). In someembodiments, the primary filter media 306 a, 306 b are arranged in aspaced apart orientation in planes that converge towards each other. Inyet other embodiments, the primary filter media 306 a, 306 b arearranged in a spaced apart orientation in planes that converge towardseach other proximate the filtered air outlet 302.

In one embodiment, the spaced apart orientation of the primary filtermedia inside the filter module may be such that the filters be angledrelative to one another so as to reduce the size of the device. When theangle is equal to 0 degrees, the filters are perfectly parallel.Conversely, when the angle is equal to 90 degrees the filters areperfectly perpendicular. As the angle increases, the loading of thefilter becomes increasingly unevenly distributed along the filter. Byway of example, an angle of 60 degrees allows for minimization of theeffects of uneven loading of the primary filter media during use yetprovides for size reduction.

With reference to FIG. 28 and FIG. 29, primary filter media 306 a, 306 bmay be secured to internal chassis 304, and internal chassis 304 withsecured primary filter media 306 may be positioned into an opening 300 ain the external housing 300 of the filer module. As described above,filter media 306 a, 306 b may be secured to the internal chassis usingfilter media retention features and spacers to facilitate placement andsecurement of the filter media. An interior perimeter of face plate 310of internal chassis 340 may be sealed to an external perimeter of asurface 320 of the external filter module housing 300, so as to form asealed exterior of filter module 106. Any suitable sealing method may beused, e.g., ultrasonic welding, thermal bonding, adhesives, etc. Onceassembled, the internal chassis 304 may be located substantially withinthe external housing 300 of filter module 106.

As illustrated, in certain embodiments, the internal chassis 304 of thefilter module 106 is positioned substantially within the external filtermodule housing 300 with an interior perimeter of face plate 310 of theinternal chassis 304 sealed to an exterior perimeter of a surface 320 ofthe external filter module housing 300 so as to form sealed exterior ofthe filter module 106. Without intending the be limited, the entirety ofthe internal chassis may be within the external filter module housing,the face plate of the filter module housing may be flush with an thesurface of an opening of the housing, portions of the internal chassis(e.g., portions of the face plate) may protrude from the housing, etc.However, in general, the internal chassis is positioned within theexternal housing such that the internal chassis may be sealed to thehousing so as to form an air tight seal between the internal chassis andthe housing to thereby form the filer module. In certain embodiments,the face plate 310 of the internal chassis 304 is sealed to a surface320 of the external filter module housing 300 using thermal bonding,ultrasonic welding, or adhesives so as to form an air tight seal betweenthe internal chassis 304 and the external filter module housing 300.

In certain embodiments, the primary filter media 306 may be formed inany suitable manner to achieve the desired filtering efficiency. Withreference to FIGS. 30A-30D, by way of example, the primary filter media306 may be comprised of a pleated composite primary filter media 400that are over-molded 402 into a structural frame 404 (or alternativelystated, the structural frame 404 is over-molded onto the filter media400). FIG. 30A illustrates a top view of an exemplary primary filtermedia, while FIG. 30B illustrates a cross-section side view in line withthe filter pleat, while FIG. 30C illustrates a cross-section side viewacross the filter pleat. FIG. 30D illustrates a detail view of theover-molding of the composite primary filter media into the structuralframe. The structural frame 404 may then be secured to the internalchassis (not shown) utilizing, e.g., securement tabs 406 in connectionwith various filter media retention features or bonding elements (notshown). As shown from FIG. 30A, securement tabs 406 may extends aroundthe entirety outside frame perimeter 410 of structural frame 404 (e.g.,as a depressed or recessed extension frame). Alternatively, securementtabs 406 may be located at defined locations around structural frame404, e.g., so as to correspond with the location of spacers 340 ofinternal chassis 304. In certain embodiments, the structural frame 404may be formed from a material selected from polypropylene oracrylonitrile butadiene styrene (ABS). In certain embodiments, thepleated composite primary filter media 400 may be over-molded 402 intothe structural frame 404 along the entire perimeter of the structuralframe 404.

In certain embodiments, with reference to FIG. 30A, structural frame 404may comprise an outside frame perimeter 410 and one or more innersupport dividers 412 to form multiple filter frame sections 414. Eachfilter frame section 414 may then comprise a pleated composite primaryfilter media 400 over-molded 402 into the filter frame section 414.Although illustrated with two dividers 412 and three filter framesections 414, the disclosure is not so limited, and any suitableconfiguration may be used, including more or fewer dividers, e.g., zerodividers so as to have a unitary filter frame section, one divider so asto have two filter frame sections, two dividers so as to have threefilter frame sections, three dividers so as to have four filter framesections, etc. Suitable configurations may be selected based on filterstructural integrity and air flow considerations, among other factors.

Any suitable method may be used to achieve the desired over-molding ofthe pleated filter into the structural frame. For instance, pleatsupport frames may be used during injection processing of the filterinto the structural frame (or alternatively states, of the structuralframe onto the filter). By way of example, the filter media may beplaced over the pleat support frame and the supported filter media maybe interfaced with a structural frame mold at the edges of the filtermedia. Structural frame materials may then be injection molded onto thesupported filter media at suitable injection temperatures and pressuresbased on the selected materials. For instance, injection temperaturesbetween, e.g., 300 to 500° F. and pressures of 600-12,000 psi may beused. However, the disclosure is not so limited.

For instance, by way of non-limiting example, the primary media 306 mayinclude any HEPA type membrane material, e.g., with a 0.1 micron-0.3micron pore size made from an inert material such aspolytetrafluoroethylene (PTFE), polyethylene terephthalate (PET),activated carbon, impregnated activated carbon, or any combination ofthe listed materials. These materials may also be, optionally,electrostatically charged. In certain embodiments, the primary filtermedia 306 may be a single pleated or sheet of material. In someembodiments, the primary filter media 306 media may be co-pleated orlaminated with other desired materials for combined benefits. By way ofnon-limited example, the primary filter media 306 may be a compositematerial including more than one layer of filter materials co-pleatedusing a thermal procedure (adhesiveless), or adhesive-based bonding toattach one or more additional layer(s) of filter material, load bearingmaterial, activated carbon for added system protection, impregnatedactivated carbon, and/or the like. In one embodiment, adhesive-basedbonding may be used, employing adhesives having low or no outgassing.Stated differently, the primary filter media 306 may be formed bybonding, co-pleating, laminating or otherwise attaching additionallayers to suitable filter materials.

In one particular embodiment, the primary filter media 306 may include alayer of ultra-high-molecular-weight polyethylene (UHMWPE) in acomposite filter stack to increase the filter efficiency. The layers ofthe primary filter media 306 may be affixed/bonded in any suitablemanner, e.g., by thermal bonding, crimping, adhesive, etc. In certainimplementations, the layers of the primary filter media 306 may bebonded by crimping the edges and pleating together by loading into acollator. In other embodiments, adhesive with a thickness range betweenapproximately 0.5 oz per square yard to 3 oz per square yard, e.g., 1 ozper square yard may be used. Without intending to be limited by theory,the adhesive may add resistance to the primary filter media 306, whichmay create and add pressure drop to the system. Alternatively, or inaddition, any adhesive may be reduced or removed to decrease pressuredrop and to reduce outgassing and VOCs emitted therefrom. If desired,activated carbon may also be added to remove VOCs (odors and chemicalfumes).

In another embodiment, the primary filter media 306 may include aplurality of thermally attached layers, including a first PE/PET layer,an activated carbon layer, a first PTFE membrane layer, a second PE/PETlayer, a second PTFE membrane layer, a third PE/PET layer, a secondactivated carbon layer, and a fourth PE/PET layer.

By way of non-limiting example, the primary filter media 306 maycomprise a pleated composite primary filter media that includes at leastthree layers in the composite media, at least five layers in thecomposite media, at least seven layers in the composite media, etc. Thelayers of the composite media may include scrim layers, membrane layers,activated carbon layers, etc. In certain embodiments, the pleatedcomposite primary filter media may comprise at least three scrim layersand at least two membrane layers. In certain embodiments, the pleatedcomposite primary filter media may have a filter pleating pitch between4 pleats to 30 pleats per inch, between 6 pleats to 24 pleats per inch,preferably between 10 pleats to 18 pleats per inch, more preferably 12pleats per inch. By way of example, the pleated composite primary filtermedia may have a filter pleat count of between 50 pleats to 100 pleats,preferably between 55 pleats to 75 pleats, more preferably between 60pleats to 65 pleats, more preferably 62 pleats.

By way of example, the size of the primary filter media may rangebetween 1.38 ft²-4.13 ft² for maximum flow rates (flow rate for highestsetting) between, e.g., 100 SLM-300 SLM. The size of the filter may bedetermined based on design requirements. By way of non-limiting example,for a pollution application, a desired airflow face velocity may beselected to not exceed 1.3 cm/s. The following equation is used todetermine the filter face velocity as a function of filter surface area:

v=QA_(s)

where v is the filter face velocity, Q is the volumetric flow rate ofthe air stream entering the filter, and A_(s), is the surface area ofthe filter.

As discussed above, in certain embodiments, the systems, device, andfilter modules of the disclosure are designed to keep the particlevelocity at the surface of the filter (face velocity) less than or equalto 5 cm/s, 4 cm/s, 3 cm/s, 2 cm/s, or 1 cm/s. In certain aspects, thislow face velocity may be achieved, at least in part, by increasing thesurface area of the primary filter component(s), e.g., by pleating theprimary filter component(s), using more than one primary filtercomponent, etc.

Without being limited by theory, the face velocity is directlyproportional to the volumetric flow rate (Q) and inversely proportionalto the surface area (A_(s)) of the filter as shown in the equation below

${v = \frac{Q}{A_{s}}}.$

In certain aspects, the surface area (A_(s)) of a filter may be greatlyincreased by pleating. The surface area of a pleated filter can becalculated using the following expression (for 1 filter):

$A_{s} = {2*L*W*d*\frac{\#{pleats}}{inch}}$

where L is the length of the pleated filter, W is the width of thepleated filter, d is the pleat depth, and #pleats/inch represents thepleat density. The equation shows that the surface area is directlyrelated to the number of pleats present on the surface so increasing theamount of pleats allows for the increase in the overall surface area anda corresponding decrease in the face velocity.

In certain embodiments, when coupled in a parallel air flowconfiguration with another filter component of the same dimensions, sucha configuration will generally generate a face velocity of less than orequal to 1 cm/s under normal operating flow rates of 80-200 SLM.Exemplary dimensional measurements are illustrated. However, thedisclosure is not so limited, and alternative dimensional configurationsare envisioned as within the scope of the disclosure.

As can be understood from FIG. 31, the filtration device 102 includes avariety of electrical components for controlling the operation of theair filtration system 100. In one implementation, the filtration device102 includes the controller 1240, one or more input devices 1202, one ormore output devices 1204, a power source 1200, such as the power source242 described herein, and one or more fans 220, such as the stackedserial axis fans described herein.

The controller 1240 receives power from the power source 1200 andmanages the distribution of the power to the various other components inthe filtration device 102. In one implementation, the controller 1240provides power to the fans 220 and a signal indicating a status of theoperations to the output device 1204 according to user input. Thecontroller 1240 accepts the user input via the input device 1202 anddictates the operation of the filtration device 102. Specifically, auser may manipulate the input device 1202 to cause the controller 1240to vary the speed of the fans 220 and consequently the flow of filteredair.

In one implementation, the input device 1202 is configured to allow auser to manipulate the operation of the filtration device 102. The inputdevice 1202 may include electromechanical devices such as switches orbuttons or may include electronic devices such as a touch screen. Theinput device 1202 may be directly connected to the controller 1240 usinga wired or wireless connection. In one implementation, the input device1202 includes the user device 112 and/or the filtration device 102. Forexample, the input device 1202 may include a single button protrudingoutward from a side of the filtration device 102 that can be found bytouch without actually having to see the button. The button is triggeredby squeezing and may include a contoured shape so that a fingernaturally comes to rest on the center of the button.

The input device 1202 may further be running an application executed bya process to generate a graphical user interface (GUI) that accepts userinputs via a touchscreen or other input method, as described herein. Inone implementation, the input device 1202 may be used to turn thefiltration device 102 on and off, select a desired fan speed, change theaesthetics of the filtration device 102 (e.g., using LEDs or one or moredisplays configured to display designs, colors, and/or graphics).

In one example, the filtration device 102 is configured to operate atlow, medium, and high settings for the fans 220. The input device 1202provides a medium for the user to select the fan speed. In oneimplementation, the input device 1202 is a button that when depressed,provides the controller 1240 with a signal. The controller 1240 receivesthe signal and is configured to cycle through the various modes ofoperation.

The output device 1204 may include any device capable of providingvisual, audible, and/or tactile feedback to the user to indicate a stateor status of the filtration device 102. The output device 1204 and theinput device 1202 may be the user device 112. In one implementation, theoutput device 1204 receives a signal indicative of a status from thefiltration device 102 and provides an output for the user. The signalprovided by the controller 1240 may include an analog or digital signalfor conveying the state or status.

In one implementation, the output device 1204 includes one or morealerts configured to indicate whether the filtration device 102 has beenactivated, a current state of the power supply 1200, a change filterindicator, a current fan speed of the filtration device 102, and/or anyother relevant status. In this example, the controller 1240 may provideanalog voltage signals to cause LEDs corresponding to the status tobecome illuminated. For example, the LEDs may be configured to include apower charge indication, a power on indication, a fan speed indicationand a change filter indication. The power on LED may include a singlewhite or other colored LED that indicates when the filtration device 102is powered on.

The power charge indication may include a group of five single colorLEDs used to indicate the current charge level of the power source 1200.When the power source 1200 is near 100% charge, all five LEDs areilluminated. Four LEDs are illuminated when the power source 1200 dropsto 80% charge, three LEDs are illuminated when the power source 1200drops to 60% charge, two LEDs are illuminated when the power source 1200drops to 40% charge, and one LED is illuminated when the power source1200 drops to 20% charge.

The fan speed indication may include three single color LEDs. A singleLED is illuminated when the fan speed is set to low, two LEDs areilluminated when the fan speed is set to medium, and three LEDs areilluminated when the fan speed is set to high. The change filterindicator may include a bi-color LED that is off when the filters are inacceptable condition, amber or yellow when the pre-filter 210 needs tobe replaced and red when the primary filter 306 needs to be replaced.

In another implementation, the output device 1204 includes a display,such as a liquid crystal display (LCD) screen that displays text andother graphical indicators for the output. In this case, the controller1240 would provide an appropriate digital signal for displaying a statuson the display. In some cases, the LCD may be on the user device 112 orother remote device.

As described herein, when the user device 112 or other computing deviceis utilized, the computing device may serve as both the input device1202 and the output device 1204. As described above, the output device1204 may include computing devices such as smart phones, tabletcomputer, and personal computers running applications configured toreceive inputs from the user and display the current status to the user.In one implementation, the user device 112 generates a GUI that allowsthe user to both control the operation of the filtration device 102 anddisplay a current status of the filtration device 102. In this example,the output device 1204 may be connected to the controller 1240 via awired or wireless connection.

The output device 1204 may further include a speaker capable ofproducing audible tones for indicating the status. In this example, thecontroller 1240 is configured to provide the output device 1204 with ananalog signal that causes a desired sound or series of sounds to beplayed by the speaker. In another example, the output device 1204 mayinclude a vibration device capable that is provided with a signal forproducing different vibration patterns depending on the status.

In one implementation, the controller 1240 is configured to manage theoperation of the fans 220 that draw air through the filters and providea user with clean air. The controller 1240 is configured to draw powerfrom the power source 1200, receive an input from the input device 1202,provide power to the fans 220, and drive an output on the output device1204. The controller 1240 may be implemented using a variety ofcomputing devices. For example, the controller 1240 may be implementedusing a general purpose computer or using smaller embedded systems suchas systems utilizing a microcontroller, microcomputer,field-programmable gate array (FPGA), or other integrated circuit orcombination of circuits.

Turning to FIG. 32, a more detailed description of the controller 1240is provided. In one implementation, the controller 1240 includes abattery manager 1208 for controlling the charging and discharging of oneor more batteries included in the power source 1200, at least one switchinput 1214 for receiving a signal or other communications for the inputdevice 1202, at least one output for indicating or sending a status ofthe filtration device 102 (e.g., a LED driver 1216), and a power outputdevice for each of the fans 220, such as pulse width modulators (PWMs)1210 for supplying each of the fans 220 with a power signal.

The PWMs 1210 may be configured to output a power signal at a frequencywithin the frequency range used by the fans 220. For example, the fans220 may operate with a peak performance when supplied with a 25 kHzpower input. Thus, the controller 1240 may operate the PWMs 1210 at afrequency of 25 kHz. Furthermore, the speed of the fans 220 may bevaried by altering the duty cycle of the PWMs 1210. For example, a lowsetting may be set at a 10% duty cycle, a medium setting may be set at a50% duty cycle, and a high setting may be set at a 100% duty cycle.

The output of the PWMs 1210 is dictated according to the user inputand/or the batter manager 1208. In one example, beginning when thefiltration device 102 is turned off, a button connected to an input onthe controller 1240 may be pressed to activate the filtration device102. Various fan speeds may be cycled through by additional buttonpresses. For example, an additional press of the button may cause thecontroller 1240 to activate the PWMs 1210 at the example 10% duty cyclethereby driving the fan(s) 220 at the low speed. An additional press ofthe button may cause the controller 1240 to up the duty cycle to 50% andthereby drive the fan(s) 220 at medium speed, and yet another press ofthe button may cause the duty cycle to be increased to 100% and the fans220 to be driven at the high speed. Additional button presses maycontinue the cycling through the various fan speeds. In one example,each press of the button causes the fan speed to cycle from low, tomedium, to high, to medium, and back to low. In this example, thefiltration device 102 may be deactivated at any time by pressing andholding the button for a preset time, such as several seconds. Inanother example, each press of the button causes the fan speed to cyclefrom low, to medium, to high, to turning the filtration device 102 off.The controller 1240 may also automatically reduce the duty cycle of thePWMs 1210 according to the current status of the power source 1200, asmonitored by the battery manager 1208, to prolong operation.

In one implementation, the battery manager 1208 determines batterycharge levels, predicts battery life, and manages the charging of thebattery when filtration device 102 is connected to a power source usingthe AC/DC converter. The battery manager 1208 may be configured tooverride a user selected fan speed and decrease the fan speed accordingto a current battery life or availability of other power sources. Forexample, if the battery life drops below a threshold and the fan speedis set to high, the controller 1240 may automatically drop the fan speedto medium once the charge threshold is reached. Similarly, if the fanspeed is set to medium and the battery charge falls below a secondthreshold, the controller 1240 may automatically reduce the fan speed tolow.

In one implementation, the battery manager 1208 includes a charger andis configured to connect the controller to one or more batteries. Thecharger supports the simultaneous charging and discharging of thebatteries. In one example, the charger includes a single charger stageconnected to the batteries via a charge MUX. The charge MUX isconfigured to allow for the charge current to be shared between each ofthe batteries while preventing charge transfer between the batteries.When charging a single battery, the battery manager 1208 adjusts thetotal current supplied by the charger to match the current required toproperly charge the battery. When there is more than one battery beingcharged, the battery manager 1208 compares the desired charge currentsfor charging each battery. The minimum charge current is then providedvia the charge MUX to each of the batteries. In this example, thebattery manager 1208 does not allow the charge current to exceed thecurrent required by any battery. Charging operates independent from theremainder of the operation, allowing for the batteries to be chargedregardless of whether the filtration device 102 is turned on or off, solong as the filtration device 102 is attached to an external powersupply.

The controller 1240 may also be configured to monitor the status of thefilter and provide feedback to the user. In one implementation, thecontroller 1240 logs when a filter is changed and tracks filter usage bylogging the amount of time that the filtration device 102 has been used.An alert may then be generated when the filter usage is close to or hasexceeded the projected lifespan of the filter. The filter usage data mayalso be adjusted by logging the amount of time at each speed that thefilter has operated. Once the filter usage limit is reached, anindicator to change the filter may be activated. For example, an LED maybe lit to indicate that the filter needs to be changed. In anotherexample, a tri-color LED may be used to indicate that a filter is good,needs to be changed soon, or needs to be changed immediately. Theindicator may also be triggered on the user device 112 or other remotedevice.

In particular implementation, the filtration device 102 has fouroperational modes dictated by the controller 1240. The modes include anoff mode, an on mode with LEDs illuminated mode, an on mode without theLEDs illuminated, and a warning mode. In this example, the off mode is avery low power mode similar to a standby mode. The filtration device 102only consumes a small amount of power when in the off mode andoperations are limited to recognizing an input being received from theinput device 1202 and turning on. Once the input is received thefiltration device 102 goes into the power on with LEDs illuminated mode.In this mode, the filtration device 102 will accept fan speed settingchanges and a command for powering off. The LEDs will be illuminated torelay the state of the filtration device 102, for example, indicatingthe fan speed, battery charge, and whether the filter needs to bereplaced. In the power on with no LEDs illuminated mode, the fan 220 iskept at its current speed and the only command that the controller 1240will recognize is to power off. The warning mode is triggered when thefiltration device 102 is engaged in one of the on modes and a problememerges. For example, the warning mode may be activated when battery isrunning low. In this case, a low battery LED may be illuminated or beginflashing. Similarly, when the filter needs to be changed an LED may beilluminated.

In one particular implementation, the controller 1240 includes a DCpower input and a protection circuit configured to protect against areverse polarity power input. When connected to an external DC powersupply, the controller 1240 controls both the operation of thefiltration device 102 and the charging of the batteries. To charge thebatteries, the controller 1240 measures the voltage of each battery andcontrols a charging current using a series of MOSFETs or other switches.Once the DC power supply has been disconnected, the controller 1240switches to drawing power from the batteries. In this example, thecontroller 1240 includes two microcontroller units operating in amaster/slave configuration. The slave microcontroller is configured tocontrol the output devices 1204, in this case by supplying the LEDdriver 1216 with a signal for lighting a plurality of LEDs to indicatecurrent operational state. The slave microcontroller unit is alsoconfigured to receive input from the input device 1202, in this case theswitch 1214. The master microcontroller unit is configured to manage thecharging of the battery and includes PWM outputs for supplying theappropriate power to the fans.

In various implementations, the components of the controller 1240 aredivided between multiple circuit boards. For example, a main board mayinclude a microcontroller, pressure sensor, a speaker, and various othercomponents, such as a voltage regulator, several choke coils forpreventing excessive current, an on/off controller, a battery charger,including the battery manager 1208 and charge circuitry. A secondcontroller board may include user interface circuitry, such as amicrocontroller, LEDS, a speaker, and a diagnostic port interface. Itwill be appreciated that these components are exemplary only and otherconfigurations and components are contemplated.

Referring to FIG. 33, a detailed description of an example computingsystem 1700 having one or more computing units that may implementvarious systems and methods discussed herein is provided. The computingsystem 1700 may be applicable to the user device 112, the filtrationdevice 102, or other computing devices. It will be appreciated thatspecific implementations of these devices may be of differing possiblespecific computing architectures not all of which are specificallydiscussed herein but will be understood by those of ordinary skill inthe art.

The computer system 1700 may be a general computing system is capable ofexecuting a computer program product to execute a computer process. Dataand program files may be input to the computer system 1700, which readsthe files and executes the programs therein. Some of the elements of ageneral purpose computer system 1700 are shown in FIG. 29 wherein aprocessor 1702 is shown having an input/output (I/O) section 1704, aCentral Processing Unit (CPU) 1706, and memory 1708. There may be one ormore processors 1702, such that the processor 1702 of the computersystem 1700 comprises a single central-processing unit 1706, or aplurality of processing units, commonly referred to as a parallelprocessing environment. The computer system 1700 may be a conventionalcomputer, a distributed computer, or any other type of computer, such asone or more external computers made available via a cloud computing orother network architecture. The presently described technology isoptionally implemented in software devices loaded in memory 1708, storedon a configured DVD/CD-ROM 1710 or storage unit 1712, and/orcommunicated via a wired or wireless network link 1714, therebytransforming the computer system 1700 in FIG. 33 to a special purposemachine for implementing the described operations.

The I/O section 1704 is connected to one or more user-interface devices(e.g., a keyboard 1716 and a display unit 1718), the storage unit 1712,and/or a disc drive unit 1720. In the case of a tablet or smart phonedevice, there may not be a physical keyboard but rather a touch screenwith a computer generated touch screen keyboard. Generally, the discdrive unit 1720 is a DVD/CD-ROM drive unit capable of reading theDVD/CD-ROM 1710, which typically contains programs and data 1722.Computer program products containing mechanisms to effectuate thesystems and methods in accordance with the presently describedtechnology may reside in the memory section 1704, on the disc storageunit 1712, on the DVD/CD-ROM 1710 of the computer system 1700, or onexternal storage devices with such computer program products, includingone or more database management products, web server products,application server products, and/or other additional softwarecomponents. Alternatively, the disc drive unit 1720 may be replaced orsupplemented by an optical drive unit, a flash drive unit, magneticdrive unit, or other storage medium drive unit. Similarly, the discdrive unit 1720 may be replaced or supplemented with random accessmemory (RAM), magnetic memory, optical memory, and/or various otherpossible forms of semiconductor based memories commonly found in smartphones and tablets.

The network adapter 1724 is capable of connecting the computer system1700 to a network via the network link 1714, through which the computersystem can receive instructions and data and/or issue file systemoperation requests. Examples of such systems include personal computers,Intel or PowerPC-based computing systems, AMD-based computing systemsand other systems running a Windows-based, a UNIX-based, or otheroperating system. It should be understood that computing systems mayalso embody devices such as terminals, workstations, mobile phones,tablets or slates, multimedia consoles, gaming consoles, set top boxes,etc.

When used in a LAN-networking environment, the computer system 1700 isconnected (by wired connection or wirelessly) to a local network throughthe network interface or adapter 1724, which is one type ofcommunications device. When used in a WAN-networking environment, thecomputer system 1700 typically includes a modem, a network adapter, orany other type of communications device for establishing communicationsover the wide area network. In a networked environment, program modulesdepicted relative to the computer system 1700 or portions thereof, maybe stored in a remote memory storage device. It is appreciated that thenetwork connections shown are examples of communications devices for andother means of establishing a communications link between the computersmay be used.

In an example implementation, filtration system control software andother modules and services may be embodied by instructions stored onsuch storage systems and executed by the processor 1702. Some or all ofthe operations described herein may be performed by the processor 1702.Further, local computing systems, remote data sources and/or services,and other associated logic represent firmware, hardware, and/or softwareconfigured to control filtration system operation. Such services may beimplemented using a general purpose computer and specialized software(such as a server executing service software), a special purposecomputing system and specialized software (such as a mobile device ornetwork appliance executing service software), or other computingconfigurations. In addition, one or more functionalities of the systemsand methods disclosed herein may be generated by the processor 1702 anda user may interact with a Graphical User Interface (GUI) using one ormore user-interface devices (e.g., the keyboard 1716, the display unit1718, and the user devices 112) with some of the data in use directlycoming from online sources and data stores. The system set forth in FIG.29 is but one possible example of a computer system that may employ orbe configured in accordance with aspects of the present disclosure.

While not limiting the scope of the disclosure, the following examplesdemonstrate efficiency of exemplary embodiments of the disclosurethrough, e.g., pressure integrity, flow momentum, superior powerefficiency, etc.

EXAMPLES Example 1: Particulate Filtration Performance Testing

The purpose of this testing is to determine the filtration performanceof exemplary filtration modules of the disclosure. The EN1822-5 teststandard is used to evaluate the filter modules, and to demonstrate thatthe filter modules have no input air “by-pass” such that seal integrityis maintained so that the air coming out of the filter module iscompletely filtered and achieves the filtration specification of thesystem.

The EN1822-5 test standard evaluates a filters' particle removalefficiency in a size range between 20 nm-300 nm. The reported efficiencyfrom the EN1822-5 testing procedure is given at the lowest measuredefficiency value recorded during the challenge. Test conditions and testresults are provided in the tables below.

-   -   Test Air Flow Rate (LPM): 400    -   Challenge Aerosol: Aerosolized KCl    -   Test Conditions Particle Measurement Equipment: TSI 3080        Classifier/TSI 3772 CNC Counter    -   Test Air Temperature (° F.): 75.2    -   Relative Humidity (%): 46.4    -   Barometric Pressure (Inches Hg): 29.54    -   Initial/Final Resistance (“WG): 0.71/0.73    -   MPPS Determination (04): 0.0209    -   Test Results Efficiency at MPPS (%): 99.99999840    -   Projected Rating (Min. Integrel for E10=85%): U17

With reference to FIG. 34, test results showed that filter modulesaccording to the disclosure achieve 99.99999% efficiency at the lowestperforming particle size region (MPPS) of the filter in the ultrafineparticle size range. This result far exceeds (3000 times better) thestandard HEPA filtration performance of 99.97% at 300 nm.

A modified Clean Air Delivery Rate (CADR) test was also performed usingan exemplary air filtration system (air filtration system includingfilter module docked in docking base) of the disclosure, comparing thelevel of ultrafine particles a test chamber room before and afterfiltration with the standard procedure of the test facility versusfiltration with a system of the disclosure. The standard procedure ofthe test facility consisted of a large HEPA filter combined with a highpowered fan that when powered on had a much higher CADR than the systemof the disclosure. The results showed that after 90 minutes of runtime,the system of the disclosure removed ultrafine particles at anefficiency greater than 99% over the entire range of particleschallenged in the room. In contrast, the standard cleaning procedureonly removed up to 85%, and form many particle sizes less than 65%.

Example 2: VOC Testing

The purpose of this testing is to determine the efficacy of airfiltration system (air filtration system including filter module dockedin docking base) of the disclosure to remove challenge VOCs. VOC removaltesting was performed referencing NRCC-54013 (April 2011): Method forTesting Portable Air Cleaners sections 3.2 and 5.1.2. Testing wasconducted for a total of 8 hours.

Natural system decay for the challenge chemicals is performed prior tothe test. The air filtration system of the disclosure was placed in thecenter of a chamber, which was then sealed and flushed with clean airfor a minimum of one night. An additional enclosure fan was operated toensure air mixing. The challenge chemicals (formaldehyde and toluene)were injected and allowed to circulate for 30 minutes during which anair sample was taken. Each challenge chemical was performed using afresh filter. The air filtration system was then turned on using thehighest fan speed beginning the test timing.

VOC samples were collected at 5, 10, 15, 20, 25, 30, 45, 60, 90, 120,180, 240, 300, 360, 420, and 480 minutes after starting the system.Samples analyzed for toluene were collected on multi-sorbent tubescontaining Tenax TA. These VOC samples were analyzed by thermaldesorption-gas chromatography/mass-spectroscopy, TD-GC/MS. Samplesanalyzed for formaldehyde were collected on cartridges treated with2,4-di-nitrophenylhydrazine (DNPH) and were analyzed using highperformance liquid chromatography, HPLC. Individual VOCs were calculatedusing calibration curves based on pure standards.

Test Parameters:

TABLE 1 Chamber conditions during test period PARAMETER SYMBOL VALUEUNITS Chamber Volume V 30 m³ Testing Duration t  8 h Test AverageTemperature T 23.6 (23.5-23.8) ° C. Conditions (Range) Average HumidityRH 49.2 (48.9-49.9) % RH (Range)

Test Results:

TABLE 2 Concentration of challenge chemical decay through test. Time(min) Formaldehyde (μg/m³) Toluene (μg/m³) D-Limonene (μg/m³) 0 180 835695 5 171 792 671 10 163 705 595 15 161 675 578 20 153 650 552 25 151616 528 30 148 605 519 45 140 488 415 60 129 431 370 90 118 301 257 120108 210 177 180 90 103 85 240 83 52 41 300 73 23 18 360 67 9 <8 420 59<8 <8 480 51 <8 <8

The clean air delivery rate (CADR) is calculated according to equation1:

$\begin{matrix}{{\ln\left( \frac{C_{t}}{C_{0}} \right)} = {{- \left( {k_{n} + \frac{CADR}{V}} \right)}t}} & {{Eq}.\mspace{14mu} 1}\end{matrix}$

where:

-   -   C_(t): chemical concentration at time t (μg/m³)    -   C₀: chemical concentration at time t₀ (μg/m³)    -   V: volume of the test chamber (m³)    -   t: time (h)    -   CADR: Clean Air Delivery Rate (m³/h)    -   k_(n): first order decay constant with PAC turned off

The single pass efficiency (SPE) is calculated according to equation 2:

$\begin{matrix}{{SPE} = \frac{CADR}{Q}} & {{Eq}.\mspace{14mu} 2}\end{matrix}$

where:

-   -   Q: purifier flow rate (27 m³/h).

TABLE 3 Purifier efficiency - calculation of clean air delivery rate andsingle pass efficiency. VOC CAS No. CADR (m³/h) SPE (%) Formaldehyde50-00-0 5.6 21 Toluene 108-88-3 18.8 69 D-Limonene 5989-27-5 18.5 68As shown in FIGS. 35 and 36, after 8 hours of testing, the airfiltration system of the disclosure removed 99% of toluene, 99% ofD-limonene, and 71% of formaldehyde.

Example 3: Virus and Bacterial Removal Efficiency

The purpose of this testing is to determine the efficacy of airfiltration system (air filtration system including filter module dockedin docking base) of the disclosure to remove viruses and bacteria.

Viral Filtration Efficiency (VFE) at an Increased Challenge Level

This test procedure was performed to evaluate the VFE of a filtrationsystem of the disclosure at an increased challenge level. A suspensionof θX174 bacteriophage was delivered to the test system at a challengelevel of greater than 10⁷ plaque-forming units (PFU) to determine thefiltration efficiency. The challenge was aerosolized using a nebulizerand delivered to the test system at a fixed air pressure and flow rateof 150 liters per minute (LPM). The aerosol droplets were generated in aglass aerosol chamber and drawn through the test system into all glassimpingers (AGIs) for collection. The challenge was delivered for a 10minute interval and sampling through the AGIs was conducted for 11minutes to clear the aerosol chamber. The mean particle size (MPS)control was performed at a flow rate of 28.3 LPM using a six-stage,viable particle, Andersen sampler for collection. The VFE at anIncreased Challenge Level test procedure was adapted from ASTM F2101.

Challenge Procedure:

The viral culture suspension was aerosolized using a nebulizer anddelivered to the test article at a constant flow rate and fixed airpressure. The aerosol droplets were generated in a glass aerosol chamberand drawn through the test system into AGIs. Approximately one third ofthe effluent air was collected for quantification during testing;therefore, the plate count results for the controls and test articleswere multiplied by three in order to reflect the entire quantity of airpassing through the test article. The challenge was delivered for a 10minute interval and the vacuum and air pressure were allowed to run foran additional minute in order to clear the aerosol chamber. Positivecontrol runs were performed (no filter medium in the air stream) priorto the first test system run, after every 5-7 test system runs, andafter the last test system run to determine the average number of viableparticles being delivered to each test system. The MPS of the challengeaerosol was determined using a six-stage Andersen sampler.

Plaque Assay Procedure:

The titer of the AGI assay fluid was determined using standard plaqueassay techniques. Approximately 2.5 mL of molten top agar was dispensedinto sterile test tubes and held at 45±2° C. in a waterbath. An aliquotof the assay fluid from the test article was added to the sterile testtubes along with approximately 0.1 mL of an Escherichia coli culture.The contents were mixed and poured over the surface of bottom agarplates. The agar was allowed to solidify on a level surface and theplates were incubated at 37±2° C. for 12-24 hours

Results:

Test Article Total PFU Recovered Filtration Efficiency (%) 01VFE123 3099.99976 02VFE121  <1^(a) >99.9999919 03VFE073  <1^(a) >99.9999919^(a)There were no detected plaques on any of the assay plates for thistest article.

The filtration efficiency percentages were calculated using thefollowing equation:

$\begin{matrix}{{\%\mspace{14mu}{VFE}} = {\frac{C - T}{C} \times 100}} & {C = {{Challenge}\mspace{14mu}{Level}}} \\\; & \begin{matrix}{T = {{Total}\mspace{14mu}{PFU}\mspace{14mu}{recovered}\mspace{14mu}{downstream}}} \\{{of}\mspace{14mu}{the}\mspace{14mu}{test}\mspace{14mu}{article}}\end{matrix}\end{matrix}$

Test Method Acceptance Criteria:

The average VFE positive control challenge level shall be ≥1×106 PFUwhen the flow rate is ≥30 LPM. The average MPS of the challenge aerosolat 1 cubic foot per minute (CFM) (28.3 LPM) must be maintained at3.0±0.3 μm.

Bacterial Filtration Efficiency (BFE) at an Increased Challenge LevelGLP Report

This test procedure was performed to evaluate the BFE of test articlesat an increased challenge level. A suspension of Staphylococcus aureus,ATCC #6538, was delivered to the test system at a challenge level ofgreater than 10⁶ colony forming units (CFU). The challenge wasaerosolized using a nebulizer and delivered to the test article at afixed air pressure and flow rate of 150 liters per minute (LPM). Theaerosol droplets were generated in a glass aerosol chamber and drawnthrough the test article into all glass impingers (AGIs) for collection.The challenge was delivered for a 10 minute interval and samplingthrough the AGIs was conducted for 11 minutes to clear the aerosolchamber. The mean particle size (MPS) control was performed at a flowrate of 28.3 LPM using a six-stage, viable particle, Andersen samplerfor collection. This method was adapted from ASTM F2101.

Culture Preparation:

Approximately 100 mL of soybean casein digest broth (SCDB) wasinoculated with S. aureus, ATCC #6538, and incubated with mild shakingfor 24±4 hours at 37±2° C. To determine the MPS of the challengeaerosol, the culture was diluted in peptone water (PEPW) to anappropriate concentration in order to yield counts within the limits ofthe Andersen sampler.

AGI Preparation:

In a laminar flow hood, a 30 mL aliquot of PEPW was dispensed into eachAGI.

Challenge Procedure:

The bacterial culture suspension was aerosolized using a nebulizer anddelivered to the test article at a constant flow rate and fixed airpressure. The aerosol droplets were generated in a glass aerosol chamberand drawn through the test article into AGIs. Approximately one third ofthe effluent air was collected for quantification during testing;therefore, the plate count results for the controls and test articleswere multiplied by three in order to reflect the entire quantity of airpassing through the test article. The challenge was delivered for a 10minute interval and the vacuum and air pressure were allowed to run foran additional minute in order to clear the aerosol chamber. Positivecontrol runs were performed (no filter medium in the air stream) priorto the first test system run, after every 5-7 test system runs, andafter the last test system run to determine the average number of viableparticles being delivered to each test system. The MPS of the challengeaerosol was determined using a six-stage Andersen sampler.

Assay Procedure:

The titer of the AGI assay fluid was determined using standard spreadplate and/or membrane filtration techniques.

Spread Plating:

An aliquot of the test article assay fluid was dispensed onto a Trypticsoy agar (TSA) plate and spread using a sterile rod.

Membrane Filtration:

A sterile filter funnel was placed on a manifold. A sterile 0.45 μmmembrane was aseptically removed from the packaging and centered overthe base of the funnel. An appropriate volume of the test article assayfluid was transferred into the sterile filter funnel. The vacuum wasapplied in order for the assay fluid to be filtered under light suction.The membrane was then rinsed to ensure that all organisms were impingedonto the membrane. The membrane was removed from the filter funnel andplaced onto the surface of a TSA plate.

All plates were incubated at 37±2° C. for 48±4 hours prior to counting.

Results:

Test Article Total CFU Recovered Filtration Efficiency (%) 01BFE164 1899.99975 02BFE035  3 99.999958 03BFE029  <1^(a) >99.999986 ^(a)Therewere no detected colonies on any of the assay plates for this testarticle.

The filtration efficiency percentages were calculated using thefollowing equation:

$\begin{matrix}{{\%\mspace{14mu}{BFE}} = {\frac{C - T}{C} \times 100}} & {C = {{Challenge}\mspace{14mu}{Level}}} \\\; & \begin{matrix}{T = {{Total}\mspace{14mu}{CFU}\mspace{14mu}{recovered}\mspace{14mu}{downstream}}} \\{{of}\mspace{14mu}{the}\mspace{14mu}{test}\mspace{14mu}{article}}\end{matrix}\end{matrix}$

Test Method Acceptance Criteria:

The average BFE positive control challenge level shall be ≥10⁶ CFU whenthe flow rate is ≥30 LPM. The average MPS of the challenge aerosol at 1cubic foot per minute (CFM) (28.3 LPM) shall be maintained at 3.0±0.3pm.

CONCLUSION

When testing for virus efficiency performance our filtration systemswere challenged with θX174 bacteriophage which is one off the smallestknown viruses (25 nm-27 nm) in size. The virus was aerosolized intoairborne droplets and filtered through an exemplary filtration system ofthe disclosure as a challenge. The result was that the systems of thedisclosure can filter out over 99.99999% of the aerosolized viral load.The test for the bacteria filtration efficiency (BFE) was conducted in asimilar fashion using an aerosolized challenge of Staphylococcus aureus.As with the VFE test, the BFE test showed that filtration systems of thedisclosure can remove over 99.99999% of the challenged bacterialaerosol.

In the present disclosure, the methods disclosed may be implemented assets of instructions or software readable by a device. Further, it isunderstood that the specific order or hierarchy of steps in the methodsdisclosed are instances of example approaches. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the method can be rearranged while remaining within thedisclosed subject matter. The accompanying method claims presentelements of the various steps in a sample order, and are not necessarilymeant to be limited to the specific order or hierarchy presented. Someor all of the steps may be executed in parallel, or may be omitted orrepeated.

The described disclosure may be provided as a computer program product,or software, that may include a non-transitory machine-readable mediumhaving stored thereon instructions, which may be used to program acomputer system (or other electronic devices) to perform a processaccording to the present disclosure. A machine-readable medium includesany mechanism for storing information in a form (e.g., software,processing application) readable by a machine (e.g., a computer). Themachine-readable medium may include, but is not limited to, magneticstorage medium, optical storage medium; magneto-optical storage medium,read only memory (ROM); random access memory (RAM); erasableprogrammable memory (e.g., EPROM and EEPROM); flash memory; or othertypes of medium suitable for storing electronic instructions.

The description above includes example systems, methods, techniques,instruction sequences, and/or computer program products that embodytechniques of the present disclosure. However, it is understood that thedescribed disclosure may be practiced without these specific details.

It is believed that the present disclosure and many of its attendantadvantages will be understood by the foregoing description, and it willbe apparent that various changes may be made in the form, constructionand arrangement of the components without departing from the disclosedsubject matter or without sacrificing all of its material advantages.The form described is merely explanatory, and it is the intention of thefollowing claims to encompass and include such changes.

Although the foregoing describes various embodiments by way ofillustration and example, the skilled artisan will appreciate thatvarious changes and modifications may be practiced within the spirit andscope of the present disclosure.

What is claimed is:
 1. An air filtration system comprising: a dockingbase including: a docking opening for receiving a portable airfiltration device in fluid communication with the docking base; one ormore unfiltered air inlets for directing unfiltered air to a portableair filtration device when docked in the docking opening; an air outletfor directing air into a portable air filtration device when docked inthe docking opening; a removable secondary media retention feature; andone or more sound dampening features to reduce air flow noise and/orvibrational noise during use; and a portable air filtration deviceincluding: a device housing including an external air intake fordirecting unfiltered air into the device; a filter module disposedwithin the housing, the filter module comprising: an external housinghaving a filtered air outlet for directing filtered air from the device;an internal chassis having a face plate including an input air inlet fordirecting input air into the filter module and a fan plenum attachmentseat for securing the filter module to a fan plenum assembly; at leasttwo primary filter media, wherein the at least two primary filter mediaare secured to the internal chassis in a spaced apart orientation in aparallel air flow configuration; and wherein the internal chassis ispositioned substantially within the external housing with the face platesealed to the perimeter of a surface of the external housing so as toform the exterior of the filter module, with the at least two primaryfilter media located within the filter module so as to separate an inputair flow region from a filtered air flow region within the filtermodule; and wherein an input, turbulent air flow region is createdwithin the filter module in a space between the spaced apart primaryfilter media during use a fan plenum assembly including at least one fanto draw input air into the device and to generate a positive pressureair flow through the device, the fan plenum assembly comprising: a fanair intake side, a fan air outlet side, and a fan plenum seal on the fanair outlet side of the fan plenum assembly interfaced with the fanplenum attachment seat of the filter module to form an air tight sealbetween the fan plenum assembly and the filter module, and wherein thefan plenum assembly is located upstream of the filter module such thatinput air flow is directed from the fan plenum assembly into the input,turbulent air flow region of the filter module during use.
 2. The airfiltration system of claim 1, wherein the internal chassis furthercomprises an input air flow path seal opposite the input air inlet, andopposed side walls, each having one or more filter media retentionfeatures that secure the at least two primary filter media to the sidewalls of the internal chassis; and wherein the input, turbulent air flowregion is created within the filter module in a space between thechassis input air inlet, the chassis input air flow path seal, thechassis opposed side walls, and the spaced apart primary filter mediaduring use.
 3. The air filtration system of claim 1, wherein the dockingbase is configured to form one or more air flow paths between the one ormore unfiltered air inlets and the air outlet.
 4. The air filtrationsystem of claim 1, wherein the one or more air flow paths are formed byan interior docking frame located between the docking opening forreceiving a portable air filtration device and the exterior of thedocking base.
 5. The air filtration system of claim 4, wherein the oneor more air flow paths form non-turbulent air flow paths.
 6. The airfiltration system of claim 4, wherein one or more of the sound dampeningfeatures are located along or adjacent to the one or more air flowpaths.
 7. The air filtration system of claim 4, wherein the removablesecondary media retention feature is located in the air flow pathbetween the one or more unfiltered air inlets and the air outlet.
 8. Theair filtration system of claim 4, wherein the docking base furthercomprises a secondary media housed in the removable secondary mediaretention feature.
 9. The air filtration system of claim 8, wherein thesecondary media comprises an activated carbon to remove volatile organiccompound (VOCs), oxides, odors, and combinations thereof.
 10. The airfiltration system of claim 9, wherein the activated carbon pre-filtermedia comprises at least two electrostatically charged scrim layersenclosing granulated activated carbon.
 11. The air filtration system ofclaim 10, wherein between 150 grams to about 175 grams is enclosedwithin the electrostatically charged scrim layers of the activatedcarbon pre-filter media.
 12. The air filtration system of claim 10,wherein the granulated activated carbon is selected from a 12×40standard sieve size coconut shell activated carbon, a 6×12 standardsieve size coconut shell activated carbon, or a 4×8 standard sieve sizecoconut shell activated carbon.
 13. The air filtration system of claim8, wherein the secondary retention feature and secondary media areconfigured to provide a desired air flow residence time through thesecondary media during use.
 14. The air filtration system of claim 8,wherein the secondary media comprises a pleated composite pre-filtermedia that is over-molded into a structural frame.
 15. The airfiltration system of claim 1, wherein the docking base further comprisesan air entry mesh at each of the one or more unfiltered air inlets toremove large particulates from unfiltered air drawn into the dockingbase during use.
 16. The air filtration system of claim 1, wherein thedocking base further comprises a power charging port in electricalcommunication with portable air filtration device when docked.
 17. Anair filtration docking base comprising: a docking opening for receivinga portable air filtration device in fluid communication with the dockingbase; one or more unfiltered air inlets for directing unfiltered air toa portable air filtration device when docked in the docking opening; anair outlet for directing air into a portable air filtration device whendocked in the docking opening; an interior docking frame located betweenthe docking opening for receiving a portable air filtration device andthe exterior of the docking base, wherein the interior docking frameforms one or more non-turbulent, unfiltered air flow paths between theone or more unfiltered air inlets and the air outlet; a removablesecondary media retention feature located in the air flow path betweenthe one or more unfiltered air inlets and the air outlet; and one ormore sound dampening features located along or adjacent to the one ormore non-turbulent, unfiltered air flow paths to reduce air flow noiseand/or vibrational noise during use;
 18. A pre-filter module comprising:a structural frame housing having a top and bottom surface at leastpartially formed from an electrostatically charged, pleated compositefilter material that is over-molded into the structural frame housing;and a granulated activated carbon media enclosed within the structuralframe housing.
 19. The pre-filter module of claim 18, wherein between150 grams to about 175 grams of granulated activated carbon media isenclosed within structural frame housing.
 20. The pre-filter module ofclaim 18, wherein the granulated activated carbon is selected from a12×40 standard sieve size coconut shell activated carbon, a 6×12standard sieve size coconut shell activated carbon, or a 4×8 standardsieve size coconut shell activated carbon.